title: [Role of ubiquitin ligase Ring2 in DNA damage induced by benzo[a]pyrene].
abstract: OBJECTIVE
  To investigate the role of ubiquitin ligase Ring2 in the DNA damage induced by benzo[a]pyrene (B[a]P).
  
  
  METHODS
  The expression of Ring2 in human bronchial epithelial (16HBE) cells was inhibited by small interfering RNA (siRNA) to obtain siRNA-Ring2 16HBE cells. The siRNA-Ring2 16HBE cells, as well as normal 16HBE cells, were exposed to B[a]P (0, 1, 2, 4, 8, 16, and 32 µmol/L) for 24 h; other siRNA-Ring2 16HBE cells and normal 16HBE cells were exposed to B [a]P (16 µmol/L) for 0, 1, 2, 4, 8, 12, and 24 h. The levels of DNA damage were evaluated by alkaline single cell gel electrophoresis assay.
  
  
  RESULTS
  After being treated with siRNA for 36 h, the siRNA-Ring2 16HBE cells showed a 72% decrease in Ring2 expression compared with normal 16HBE cells. The analysis of covariance showed that whether to be treated with siRNA and concentration of B[a]P had impacts on Olive tail moment (OTM) (P = 0.032 and P < 0.001); the adjusted mean of OTM was significantly higher in siRNA-Ring2 16HBE cells than in normal 16HBE cells. Whether to be treated with siRNA and B[a]P exposure time had impacts on OTM (P = 0.031 and P < 0.001); the adjusted mean of OTM was significantly higher in siRNA-Ring2 16HBE cells than in normal 16HBE cells.
  
  
  CONCLUSIONS
  The DNA of 16HBE cells with decreased Ring2 expression has increased susceptibility to B[a]P, which may be due to reduced H2A monoubiquitination following decrease in Ring2 expression.
authors.affiliation: Department of Occupational Health, School of Public Health, Shanxi Medical University, Taiyuan 030001, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Yang
authors.forename: Zhi-wu
authors.initials: ZW
authors.lastname: Wang
authors.forename: Cheng-yun
authors.initials: CY
authors.lastname: Liu
authors.forename: Jin-zhu
authors.initials: JZ
authors.lastname: Yin
mesh_terms: D001564:Benzo(a)pyrene / Q000633:toxicity*; D001980:Bronchi / Q000166:cytology; D002460:Cell Line; D004249:DNA Damage / Q000187:drug effects*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*; D043222:Ubiquitin Thiolesterase / Q000235:genetics / Q000378:metabolism*
chemical_list: C400134:BAP1 protein, human; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins; D001564:Benzo(a)pyrene; D043222:Ubiquitin Thiolesterase